JPH0599556A - Controller of freeze refrigerator - Google Patents

Abstract

PURPOSE:To provide a controller for a freeze refrigerator that eliminates a rise in temperature of foods due to insufficient precooling or due to an excess of precooling by carrying out precooling right before defrosting according to the largeness of thermal load to the foods in the refrigerating member. CONSTITUTION:The temperature in the subject refrigerating refrigerator is detected by a temperature sensor 21, and when a cumulative time counter 22 for the operation of a compressor counts a set time, the cooling time from the standard value of a second-standard circuit 25 to the standard value of a fourth standard circuit 32 is measured by a cooling time measurement means 31. From this cooling time and the ambient temperature detected by an ambient temperature sensor 30 a fuzzy-theoretical calculation is carried out based on a control rule taken out from a memory 34 by a fuzzy inference processor 33 to determine the time of precooling and precooling time is set by a time setting means 35 for the timer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defrosting control of a refrigerator / freezer (hereinafter referred to as a refrigerator) based on an empirical rule and a fuzzy variable membership function forming the control rule. The present invention relates to a refrigerator-freezer control device that minimizes an increase in internal temperature and eliminates the influence on food.

[0002]

2. Description of the Related Art A control device for a refrigerator / freezer operates a fan motor, a compressor and an electric damper so as to control each of a refrigerator compartment, a refrigerator compartment and a vegetable compartment of a refrigerator at a set temperature. Furthermore, by energizing the defrost heater, it removes the frost adhering to the cooler,
For example, Japanese Patent Publication No. 2-53707 and Japanese Patent Publication No. 2-631.
No. 53 publication.

A conventional control device for a refrigerator-freezer will be described below with reference to the drawings. FIG. 7 is a block diagram of a conventional refrigerator-freezer control device, and FIG. 8 shows a configuration of a conventional refrigerator-freezer. Reference numeral 1 is a refrigerator main body, which is an outer box 2 and an inner box 3 and a urethane foam insulating material 4 formed in a space between them.
And the three doors 5, 6, 7 are arranged in the front opening. The doors 5, 6, and 7 are arranged corresponding to the openings of the freezer compartment 8, the refrigerator compartment 9, and the vegetable compartment 10 of the refrigerator body 1, respectively.

A bottom plate 11 of the freezer compartment 8 and a top plate 12 of the refrigerating compartment 9
Inside the partition wall surrounded by, there is a cooler 13 and a cooling fan 14 behind it. Further, ventilation paths 15 and 16 for introducing cooling air from the cooler 13 into the respective compartments are formed at the backs of the freezing compartment 8 and the refrigerating compartment 9. Reference numeral 17 is a compressor. Reference numeral 18 is a freezing compartment door switch that operates by opening and closing the door 5 of the freezing compartment 8, 19 is a freezing compartment temperature sensor, and 20 is a defrosting heater that removes frost adhering to the cooler 13.

Further, reference numeral 21 is an in-compartment temperature detecting means for electrically converting the output of the freezer compartment temperature sensor 19 and outputting it.
Reference numeral 22 is a compressor operation time integration timer that integrates the operation time of the compressor.

Reference numeral 23 is a cooling control means. This cooling control means 23 turns on the compressor 17 and the cooling fan 14 when the output of the inside temperature detection means 21 reaches the reference value of the first reference circuit 24, and turns on the reference value of the second reference circuit 25. When the compressor operating time integration timer 22 reaches the set time and outputs the defrosting start signal, the output of the internal temperature detecting means 21 reaches the reference value of the third reference circuit 26. The compressor 17 and the cooling fan 14 are turned on, and then a defrosting execution signal is output to the defrosting control means 27.

Here, the relationship among the reference values of the first reference circuit 24, the second reference circuit 25, and the third reference circuit 26 is in descending order of temperature. That is, the inside temperature detecting means 2
When the output of 1 is the same as that of the first reference circuit 24, the inside temperature is lower when it is the same as that of the second reference circuit 25, and when it is the same as that of the third reference circuit 26, The temperature is low.

When the defrosting execution signal is input, the defrosting control means 27 turns on the defrosting heater until the signal from the defrosting completion detecting means 28 is input to remove the frost on the cooler 13.

When the defrosting is completed, the defrosting control means 27 outputs a defrosting control end signal to the cooling control means 23, and the cooling control means 23 restarts the cooling control.

The operation of the refrigerator-refrigerator control apparatus configured as described above will be described below with reference to the flowchart of FIG.

First, the inside temperature detecting means 22 detects the temperature of the freezer compartment and compares it with the reference value of the first reference circuit 24 (step 101). If the temperature is low, the reference value of the second reference circuit 25 is used. If the temperature is low, the compressor 17 and the cooling fan 14 are turned off in step 103. If the temperature is high, step 104
If it is OFF, it is judged whether the compressor 17 is ON, and the process returns to step 101. If it is ON, step 1
Proceed to 06.

If the temperature is high in step 101, the compressor 17 and the cooling fan 14 are operated in step 105.
Is turned on, and in step 106, the compressor operation time integration timer 22 integrates the operation time of the compressor. Next, at step 107, it is judged whether the integration time of the compressor operation time integration timer 22 has reached the set time.

If the set time is not reached, the process returns to step 101, and if the set time is reached, the step 1 is performed.
At 08, the integration of the compressor operating time integration timer 22 is stopped, the contents are initialized, the in-compartment temperature is compared with the reference value of the third reference circuit 26, and the in-compartment temperature becomes the reference value of the third reference circuit 26. Compressor 17 and cooling fan 14 until reaching
When the internal temperature reaches the reference value of the third reference circuit 27, the compressor 17 and the cooling fan 14 are turned off in step 109. This is because the temperature inside the refrigerator is increased by defrosting, so that the inside of the refrigerator is cooled to a normal temperature in advance (hereinafter referred to as precool).

Then, in step 110, the defrosting heater 2
0 is turned on, and the defrosting heater 20 is turned on until the defrosting completion detecting means 29 detects the completion of defrosting (step 111). Then, when it is finished, the defrosting heater 20 is turned off in step 112, and the process returns to step 101.

[0015]

However, in the above structure, the pre-cooling before defrosting is constant regardless of the state of the inside of the refrigerator (internal temperature, heat load of food, etc.). When there is a lot of food, the heat load of the pre-cooled is large, so the temperature rise in the refrigerator during defrosting is small, the pre-cooling time is too long, and the electricity is increased. There was a problem that the temperature inside the refrigerator during defrosting was large and the pre-cooling time was too short to raise the temperature of the food inside the refrigerator.

The present invention solves the above problems.
An object of the present invention is to provide a control device for a freezer-refrigerator that can perform a fine pre-cool by calculating an operation amount according to a heat load amount of food in the freezing chamber.

[0017]

In order to achieve the above object, a control device for a refrigerator / freezer of the present invention is a refrigerator / freezer capable of freezing or refrigerating and storing food, and a freezer compartment provided in the freezing compartment. A temperature sensor, an inside temperature detecting means for detecting the inside temperature of the freezing room by the freezing room temperature sensor, a cooling time measuring means for measuring the time for the inside temperature to drop from a set temperature to a certain temperature, and an outside The temperature of the outside air detecting means for detecting the temperature, the outside air temperature detected by the outside air temperature detecting means, the cooling time measuring means, the memory for storing the control rule based on the empirical rule for obtaining the precool time, and the memory taken out from the memory. Fuzzy inference processor which performs fuzzy logic operation and precool time based on the control rule Timer time setting means for setting the pre-cooling time, cooling control means for driving the compressor and the cooling fan by the output of the internal temperature detection means, and energization of the defrost heater to control the temperature of the cooler to detect the constant temperature. In this case, there is provided a defrosting control means for ending the defrosting by the output of the defrosting completion detecting means for outputting the defrosting completion signal.

[0018]

According to the present invention, the heat load of the food in the refrigerator is detected from the temperature decrease time measured by the cooling time measuring means and the outside air temperature detected by the outside air temperature detecting means, and the control rule in the memory is adopted. Based on this, the fuzzy inference processor performs fuzzy logic operation, so that the precool time corresponding to the heat load amount is obtained. Therefore, based on the operation amount obtained above, the cooling control means controls the compressor and the cooling fan to perform precooling, and then the defrosting control means controls the defrosting heater to defrost the inside of the refrigerator. Pre-cooling can be performed according to the amount of heat load of the food inside, and it is possible to prevent temperature increase of the food due to insufficient pre-cooling and power increase due to excessive pre-cooling.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A control device for a refrigerator-freezer according to an embodiment of the present invention will be described below with reference to the drawings. Detailed description of the same parts as the conventional one will be omitted.

FIG. 1 is a block diagram of a control device for a refrigerator / freezer in an embodiment of the present invention, and FIG. 2 shows a structure of the refrigerator / freezer. FIG. 3 (I) is a graph showing a membership function of a fuzzy variable with respect to a temperature decrease time in the embodiment of the present invention, and FIG. 3 (II) is a graph showing a membership function of a fuzzy variable with respect to an outside temperature in the embodiment of the present invention. 4 is a flow chart for explaining the operation in the embodiment of the present invention, and FIG. 5 is a flow chart for explaining the procedure of fuzzy inference in the embodiment of the present invention.

1 and 2, reference numeral 29 is an outside air temperature sensor for detecting the temperature of the place where the refrigerator is installed, and 30 is an outside air temperature sensor for electrically converting and outputting the output of the outside air temperature sensor 29. It is a means.

Reference numeral 31 is a cooling time measuring means, which is an inside temperature detecting means 21, a compressor operating time integrating timer 22, and a second.
Is connected to the outputs of the reference circuit 25 and the fourth reference circuit 32, and the output of the cooling time measuring means 31 is connected to the fuzzy inference processor 33. The cooling time measuring means 31 measures the temperature decrease time from the reference value of the second reference circuit 25 to the reference value of the fourth reference circuit 32 when the compressor operation time integration timer 22 reaches the integration time. .. A memory 34 stores a control rule based on an empirical rule for obtaining the precool time.

The fuzzy inference processor 33 is connected to the cooling time measuring means 31 and the outside air temperature detecting means 30, and the amount of heat load in the refrigerator which can be detected from the outputs of both is determined by the control rule retrieved from the memory 34. Based on this, fuzzy logic operation is performed to calculate the pre-cool time.

As shown in FIG. 6, the heat load in the refrigerator is detected from the reference value of the second reference circuit 25 to the reference value of the fourth reference circuit 32 when the already cooled heat load in the refrigerator is small. When the heat load of the already cooled inside of the refrigerator is large, the temperature decrease time from the reference value of the second reference circuit 25 to the reference value of the fourth reference circuit 32 becomes long. When the outside air temperature is low, the temperature decrease time is short, and when the outside air temperature is high, the temperature decrease time is long.

Further, 35 is a fuzzy inference processor 33.
The timer time setting means for setting the pre-cool time calculated by the above, and its output is connected to the cooling control means 36. This cooling control means 36 is for performing cooling control, and the output of the inside temperature detection means 21 is the first reference circuit 24.
If the standard value of is reached, the compressor 17 and the cooling fan 14
Is turned on, and turned off when the reference value of the second reference circuit 25 is reached.
The compressor operating time integration timer 22
Is set time and the defrosting start signal is output, the compressor 17 and cooling are performed for the time set by the timer time setting means 35 after the output of the inside temperature detection means 21 reaches the reference value of the fourth reference circuit 32. The fan 14 is turned on, and then a defrosting execution signal is output to the defrosting control means 27. Here, the first reference circuit 24, the second reference circuit 25, and the fourth reference circuit 25
The relationship between the reference value of the reference circuit 32 and the reference value is in descending order of temperature.

That is, the inside temperature is lower when the output of the inside temperature detecting means 21 is the same as the second reference circuit 25 than when the output is the same as that of the first reference circuit 24, and the fourth reference is lower than that. The temperature inside the refrigerator is lower when the temperature is the same as that of the circuit 32.

When the defrosting execution signal is input, the defrosting control means 27 turns on the defrosting heater until the defrosting completion detecting means 28 is input, and removes the frost on the cooler 13.

The operation of the control device for the refrigerator-freezer having the above-described structure will be described below with reference to FIGS. 1 to 4.

Here, step 101 to step 107
Up to the above, the operation is the same as that of the control device of the conventional refrigerator-freezer.

When it is determined in step 107 that the integrated time of the compressor operating time integration timer 22 is the set time, the process proceeds to step 113 and the compressor 17 is operated until the internal temperature reaches the reference value of the second reference circuit 25. Also, the cooling fan 14 is turned on to cool the inside of the refrigerator.

When the internal temperature reaches the reference value of the second reference circuit 25, the process proceeds to step 114, and the cooling time measuring means 31 lowers the temperature until the internal temperature reaches the reference value of the fourth reference circuit 32. Start measuring time. Next step 1
In step 15, it is determined whether the internal cold storage temperature has reached the reference value of the fourth reference circuit 32. If the internal cold storage temperature has reached the reference value of the fourth reference circuit 32, then in step 116 the temperature decrease time is calculated.
Then, in step 117, the outside air temperature detecting means 30 detects the outside air temperature.

Then, the temperature decrease time calculated by the cooling time measuring means 31 and the outside air temperature detected by the outside air temperature detecting means 30 are inputted to the fuzzy inference processor 33, and the fuzzy inference processor 33 previously stores the memory 34.
The control rule stored in is extracted, the precool time is calculated by fuzzy inference, and the precool time is set in the timer time calculation means 35 (step 11).
8).

Then, the compressor 17 and the cooling fan 1 are operated until the precool time set in step 119 is reached.
Turn on 4 to cool the inside of the refrigerator. Then, when the set time of the pre-cool is reached, the compressor 17 and the cooling fan 14 are turned off in step 109, as in the operation of the control device of the conventional refrigerator-freezer.

Then, in step 110, the defrosting heater 2
0 is turned on, and the defrosting heater 20 is turned on until the defrosting completion detecting means 29 detects the completion of defrosting (step 111). Then, when it is finished, the defrosting heater 20 is turned off in step 112, and the process returns to step 101.

Here, the fuzzy inference for obtaining the optimum precooling time of the cooler is executed based on the following control rule.

First, in order to obtain the pre-cool time, the control rules adopted in this embodiment are the following nine rules. For example, rule 1: If the temperature drop time is long and the outside air temperature is low, shorten the precool time. Rule 2: If the temperature drop time is normal and the outside air temperature is low, shorten the precool time a little.

··· Rule 5: If the temperature drop time is normal and the outside air temperature is medium, normalize the precool time.

Rule 9: If the temperature decrease time is short and the outside air temperature is high, increase the precool time. Etc.

This is because if the temperature decrease time is long, the heat load of already cooled is large and the temperature rise in the cold storage during defrosting is small. Therefore, the precool time may be shortened, and if the outside air temperature is high. This is a rule obtained from experience that the temperature inside the refrigerator during defrosting is large, so the pre-cool time must be extended. Therefore, the above language rule was found by the inventor from a large number of experimental data,
This is a control rule for the precooling time during which the precooling can be performed in the optimum defrosting control of the cooler, and it is as shown in Table 1 in terms of the relationship between the temperature lowering time and the outside air temperature.

[0040]

[Table 1]

(Table 1) is a table showing the relationship of the control rules, in which the temperature decrease time T has three levels in the horizontal direction (LT = long, MT).
= Middle, ST = Short), and the outside air temperature A is divided into three stages (LA = High, MA = Medium, SA = Low) in the vertical direction, and the temperature decrease time and the outside air temperature are divided. At each intersecting position, the temperature decrease time and the optimum pre-cool time corresponding to the outside air temperature are arranged in 5 stages (VLP = long, LP = a little long, MP = medium, SP = a little short, VSP = short). ing.

Further, the language rule is stored in the memory 31 of FIG.
When stored in, it is stored according to the following rule rule. The control rules adopted in this embodiment are nine. Rule 1: IF T is LT and A is SA THEN P is VSP Rule 2: IF T is MT and A is SA THEN P is SP ... Rule 5: IF T is MT and A is MA THEN P is MP. 9: IF T IS ST and A is LA THEN P is VLP Control Rule 1, Rule 2 ... The rule of Rule 9 is such that the temperature decrease time T, the outside air temperature A, and the precool time P are stepped as shown in (Table 1). Therefore, in the case of performing fine control, the measured temperature decrease time in the middle of each stage of the temperature decrease time T and the outside air temperature A, the outside air temperature,
It is necessary to calculate the degree to which the antecedent part (IF part) of the control rule is satisfied and to estimate the pre-cool time according to the degree. Therefore, in the present embodiment, this degree is calculated using the membership function of the fuzzy variable with respect to the temperature decrease time T and the outside air temperature A.

FIG. 3 (I) shows the membership function μST of the fuzzy variables ST, MT, LT with respect to the temperature decrease time T.
(T), μMT (t), μLT (t) are shown, and FIG. 3 (II) shows membership functions μSA (a), μ of the fuzzy variables SA, MA, LA with respect to the outside air temperature A.
It shows MA (a) and μLA (a). The fuzzy inference executed by the fuzzy inference processor 33 is the control rule 1, rule 2, ... Rule 9 and FIG.
A fuzzy logic operation is performed using the membership function (II) and the operation amount is calculated.

The procedure of fuzzy inference, which is step 118 of FIG. 4, will be described below with reference to the flowchart of FIG.

In step 120, the fuzzy inference processor 33 uses the membership function of the fuzzy variable for the temperature decrease time t0 and the outside air temperature a0 to determine the membership value at the temperature decrease time t0 and the outside air temperature a0 (M value in the figure). Display) is calculated.

In step 121, the degree to which the membership value of the fuzzy variable for the obtained temperature decrease time t0 and the outside air temperature a0 satisfies the antecedent part of each of the nine rules is synthesized as follows. Calculate by the method.

In the figure, the fuzzy variable for the temperature decrease time is indicated by α, and the fuzzy variable for the outside air temperature is indicated by β. Rule 1: h1 = μLT (t0) ∩μSA (a0) = MIN {μLT (t0), μSA (a0)}-(1) Rule 2: h2 = μMT (t0) ∩μSA (a0) = MIN { μMT (t0), μSA (a0)} --- (2) Equation (1) shows that t0 is a region L with respect to the temperature decrease time T.
When T is entered and a0 is an area SA for the outside air temperature A
The proposition to enter is the rate that t0 enters LT and a0 is SA
It is expressed that a small value out of the input ratio is satisfied, that is, the antecedent part of rule 1 is satisfied at a ratio of h1. Similarly, in the case of the rule 2 of the equation (2), the antecedent portion is satisfied at the rate of h2.

In step 122, the precooling time at the temperature decrease time t0 and the outside air temperature a0 is determined by the membership function of the execution part of the control rule as follows. The pre-cool time pt0 is expressed by (Equation 1) as the value of the weighted average of the proportions h1, h2, ... h9 in which the antecedent part of each control rule holds, using the height method which is one of the one-point conversion methods. Calculate as shown.

[0049]

[Equation 1]

As a result, the precool time pt0 is obtained. Therefore, in this embodiment, since the temperature decrease time and the outside air temperature are used as the control parameters, fine control is possible. In addition, since the control rule is based on human experience, precooling can be performed in the defrosting control of the cooler in the optimum precooling time.

[0051]

As described above, the present invention provides a freezer-refrigerator capable of freezing or refrigerating food and storing it.
The freezing room temperature sensor provided in the freezing room, the indoor temperature detecting means for electrically converting and outputting the internal room temperature in the freezing room by the freezing room temperature sensor, and the operating time of the compressor are integrated to calculate the operating time. A compressor operation time integration timer that outputs a signal when the set time is reached, a cooling time measurement unit that measures the time when the temperature inside the refrigerator decreases from the set temperature to a certain temperature by the signal of the compressor operation time integration timer, and Outside temperature detecting means for detecting the temperature, a memory for storing a control rule based on an empirical rule for obtaining the cooling time before defrosting, an outside temperature detected by the outside temperature detecting means, and a cooling time measuring means Fuzzy logic operation that calculates the cooling time before defrosting based on the temperature decrease time and the control rule retrieved from the memory. Logic processor, a timer time setting means for setting the cooling time before defrosting calculated by the fuzzy inference processor, a cooling control means for driving the compressor and the cooling fan by the outputs of the internal temperature detection means and the timer time setting means, Control the energization of the defrost heater,
By including the defrosting control means that detects the temperature of the cooler and outputs the defrosting termination signal when the temperature reaches a constant temperature, the defrosting termination detecting means outputs the defrosting termination signal. It is possible to perform pre-cooling according to the heat load amount of the food in the refrigerator, and it is possible to prevent temperature increase of the food due to lack of pre-cooling and increase in power due to excessive pre-cooling.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device for a refrigerator-freezer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a refrigerator-freezer in the same embodiment.

FIG. 3 (I) is a graph showing a membership function of a fuzzy variable with respect to a temperature decrease time in the same embodiment. (II) is a graph showing a membership function of a fuzzy variable with respect to the outside air temperature in the same embodiment.

FIG. 4 is a flowchart for explaining the operation in the same embodiment.

FIG. 5 is a flowchart for explaining a fuzzy inference procedure in the embodiment.

FIG. 6 is a diagram showing the relationship between the temperature decrease time and the internal load in the same embodiment.

FIG. 7 is a block diagram of a conventional controller for a refrigerator-freezer.

FIG. 8 is a block diagram of a conventional refrigerator-freezer.

FIG. 9 is a flowchart for explaining the operation in the conventional example.

[Explanation of symbols]

 19 Freezing room temperature sensor 21 In-compartment temperature detection means 22 Compressor operating time integration timer 25 Second reference circuit 27 Defrosting control means 28 Defrosting completion detecting means 29 Outside air temperature sensor 30 Outside air temperature detecting means 31 Cooling time measuring means 32 Fourth Reference circuit 33 Fuzzy inference processor 34 Memory 35 Timer time setting means 36 Cooling control means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Hayashi Inventor Hideo Hayashi 3-22 Takaidahondori, Higashiosaka City, Osaka Prefecture Matsushita Refrigerating Machinery Co., Ltd.

Claims (1)

[Claims] 1. A freezer-refrigerator capable of freezing or refrigerating and storing foods, wherein a freezer compartment temperature sensor provided in the freezer compartment and the freezer compartment temperature sensor electrically convert a compartment temperature in the freezer compartment. The internal temperature detection means for outputting the internal temperature of the refrigerator and the compressor operating time integration timer that integrates the operating time of the compressor and outputs a signal when the operating time reaches the set time Cooling time measuring means that measures the time it takes for the temperature to drop from the set temperature to a certain temperature, outside air temperature detecting means that detects the temperature outside the refrigerator, and control rules based on empirical rules for determining the cooling time before defrosting are stored. The memory, the outside air temperature detected by the outside air temperature detecting means, and the temperature decrease time calculated by the cooling time measuring means from the memory. Based on the extracted control rule, fuzzy inference processor that performs fuzzy logic operation to calculate the cooling time before defrosting, timer time setting means that sets the cooling time before defrosting calculated by the fuzzy inference processor, and Cooling control means for driving the compressor and cooling fan by the outputs of the internal temperature detection means and the timer time setting means, and the energization of the defrosting heater are controlled, the temperature of the cooler is detected, and a defrosting completion signal is output if a constant temperature is reached. And a defrosting control unit for ending defrosting according to the output of the defrosting completion detecting unit.